Purdeys drop trigger o/u has been made by Peruginii & Visini in Italy. The guns were finished in England. Dont know if that is still the case.
That was also my understanding. Various English 'top names' are made in other places, and some 'top names' are more open about it than others! (For example some Powell guns have for many years been made in Spain and Italy, something which Powells have always been quite open about).
I believe William Evans has some guns made in Italy or Spain also. The better guns could be uk made but i do not know for certain. Its a well worn path, BSA had guns made by SKB in Japan back in the 1960's, very good guns they were too. Some of the old Webley side by sides were made in Spain. Now they are made entirely in Turkey.
But even back in the great days of English gunmaking, a lot of parts and components were sourced from Belgium.
